I had that a year or so ago. It lasted for what seemed forever. I got it from shoveling dirt trying to landscape/grade my side yard. You just need to let it rest and heal - it will eventually go away.
With you @dleq A lot we don’t fully know yet and we are a long way from being done with this. If we get a vaccine by the end of the year, it will be like the modern day accomplishment of landing on the moon.
All
but seriously you may not need to spend a lot of time on Math and Plant Engineering. Obviously spend a lot of time on HVAC and systems that you use in HVAC: pumps, boilers, chillers, motors, controls.
Finally got the bike out and did 17 mi on the bike path. Not too many out there, but I’m guessing the weekend will be mobbed. I going to be hurting tomorrow, so I might as well have a beer.